Natural rubber latex allergy and asthma

Allergic responses to natural rubber latex (NRL) continue to be reported. In adults, the major exposure is in the occupational setting, especially in relation to NRL glove use by health care workers. Issues addressed over the past year include improving diagnostic methods for NRL allergy and characterization of NRL allergens relevant to various exposure groups and evaluating strategies for prevention and early detection of NRL allergy. Assessment of in vitro tests show good intertest correlation but lower sensitivity compared with skin test responses. NRL allergens have been further characterized as reported in the past year. Development of recombinant Hev b 3, a major NRL allergen relevant to children with spina bifida, enhances the likelihood for improved diagnostic reagents. Preliminary reports of primary preventive strategies suggest that avoidance of high-protein, powdered gloves in health care facilities can be cost-effective and is associated with a decline in sensitized workers.     

Hev b 6.02 Is the Most Important Allergen in Health Care Workers Sensitized Occupationally by Natural Rubber Latex Gloves

BackgroundNatural rubber latex (NRL) allergy is a common occupational disease in health care workers (HCW). However, few reports have compared the major allergen of HCWs to those in gloves that are routinely used in the hospital. The aim of this study was to evaluate the major NRL allergens in gloves used by HCWs.MethodsWe studied 20 HCWs who were suspected to have latex allergy (LA). We performed a skin prick test (SPT) using NRL allergens. Serological testing was performed using the ImmunoCAP?. The total amount of protein and the antigenic protein concentrations extracted from NRL gloves were measured. Four different types of FITkit? were used to measure the concentrations of Hev b 1, 3, 5, and 6.02 in the gloves.ResultsA SPT using NRL extract identified 14 cases with positive reactions. The sensitivity and specificity of the SPT scores to the NRL glove extract were 100%. The sensitivity of latex specific IgE was 100% but the specificity was 14.2%. The sensitivity and specificity of rHev b 6.02 specific IgE were 100% in the LA group. The total amounts of protein from the medical gloves for surgery and examination were 265 μg/g and 95 μg/g, respectively. The antigenic protein concentrations in the gloves were 24.9 μg/g and 1.0 μg/g, respectively. The total amounts of the specific four allergens in the NRL gloves were 2.18 μg/g and 0.45 μg/g, respectively.ConclusionsWe concluded that the main allergen of HCWs who have been sensitized occupationally by NRL gloves was Hev b 6.02.     

Addressing Molecular Diagnosis of Occupational Allergies

Purpose of Review

Numerous clinically relevant allergenic molecules enhance the performance of specific (s) IgE tests and improve the specificity of allergy diagnosis. This review aimed to summarize our current knowledge of the high-molecular-weight allergens involved in the development of occupational asthma and rhinitis and to critically analyze the contribution of component-resolved diagnosis in the management of these conditions.

Recent Findings

There is a lack of standardization and validation for most available extracts of occupational agents, and assessment of sIgE reactivity to occupational allergen components has been poorly investigated, with the notable exception of natural rubber latex (NRL) and wheat flour. In the case of NRL, the application of recombinant single allergens and amplification of natural extracts with stable recombinant allergens improved the test sensitivity. IgE-sensitization profile in patients with baker’s asthma showed great interindividual variation, and extract-based diagnostic is still recommended. For other occupational allergens, it remains necessary to evaluate the relevance of single allergen molecules for the sensitization induced by occupational exposure.

Summary

Progress has been made to characterize occupational allergens especially NRL and wheat, although there is still an unmet need to increase the knowledge of occupational allergens, to include standardized tools into routine diagnostic, and to evaluate their usefulness in clinical practice.

     

Prevalence of latex allergy and evaluation of some risk factors in a population of atopic children.

The aims of our study were to evaluate (1) the prevalence of natural rubber latex (NRL) allergy in an unselected population of atopic children; (2) the diagnostic efficacy of skin prick tests (SPTs) with latex extracts; (3) the correlation between positive SPTs to latex and risk factors such as atopy, fruit allergy, history of surgery cares or dental cares. We randomly enrolled 151 unselected atopic and 59 nonatopic children who underwent SPTs with common inhalant and food allergens, and SPTs with two different latex extracts. A clinical history concerning allergic history, symptoms after contact with latex objects or after ingestion of fruits or vegetables, dental and surgical treatments was obtained. Six of the 151 atopic children were positive to latex SPTs, but only one out of 59 nonatopic children was positive to latex SPTs. Concerning risk factors, 86% of children with SPT positive to latex were atopic, 71.4% had a clinical history of surgery, and none of them had undergone dental or orthodontic treatments. The prevalence of NRL sensitization in our unselected population of atopic children was 3.9%, but the prevalence of NRL allergy was 2.6%. Concerning NRL allergy, the sensitivity and the specificity of SPTs with latex extracts are high (1.00 and 0.98, respectively), as well as negative predicting value (1.00); the positive predictive value is low (0.70). We conclude that atopy, surgical treatments, and sensitization to foods cross-reacting with NRL are important risk factors for NRL sensitization. We have no data concerning dental or orthodontic cares.     

Laboratory tests for diagnosis of food allergy: advantages,disadvantages and future perspectives

Numerous biological tests point to the diagnosis of food sensitization: detection of specific IgEs by Rast techniques, multi-detection assays, immunoblotting, screening of basophil activation (BAT or FAST), assays for leukotriene LTC4 release (CAST), measurement of plasma histamine, serum tryptase, serum ECP, urinary EDN, completed by mannitol-lactulose test evaluating intestinal permeability, assay of fecal IgEs, Rast for specific IgG4. Primary screening for anti-food IgEs by multi-detection assays seeks justification from insufficient clinical data and false positive tests are common in patients sensitized to pollens or latex, on account of in vitro cross reactivities (CR). Multiple CR explain positive Rast to vegetal food allergens in such patients. Biological tests should not be performed as the first line of diagnosis. In vivo sensitisation is assessed by positive prick-tests, demonstrating the bivalence of allergens, as well as the affinity of specific IgEs, two conditions necessary to bridge membrane bound specific IgEs, leading to the release of mediators. Prick-tests are closer to clinical symptoms than biological tests. However, the diagnosis of food allergy is based on standardised oral challenges. Exceptions are high levels of specific IgEs to egg (> 6 kUl/l), peanut (> 15 kUl/l), fish (> 20 kUl/l) and milk (> 32 kUl/l), reaching a 95% predictive positive value. Rast inhibition tests are useful to identify masked allergens in foods. Research developments will have impact on the development of new diagnostic tools: allergen mixes reinforcing a food extract by associated recombinant major allergens, multiple combination of recombinant allergens (chips) or tests with synthetic epitopes aimed a the prediction of recovery. Laboratory tests take place in the decision free for the diagnosis for the food allergy and the follow-up of the levels specific IgEs is a tool to assess outcome and contributes to predict recovery or persistent allergy. Up to now the significance of positive laboratory tests showing the implication of IgEs is at the crossroads of the allergist's and biologist's expertise.     

Why can patients with baker's asthma tolerate wheat flour ingestion? Is wheat pollen allergy relevant?

Diagnosis in patients sensitised to multiple pollens is difficult due to the relationship between pollen and food allergens. Misdiagnosis is often a cause for unsuccessful specific immunotherapy. Wheat is a potent allergen source and is one of the causes of baker's asthma, food and pollen allergy. Recently, we have performed a study on pollen sensitisation in our area, where cereal crops are very important. The clinical data from 19718 patients reviewed showed that grass pollen was the main source of clinical symptoms (6369 patients, 32.30% of asthmatics). However, wheat and cereal crop pollen showed very low prevalence. On the other hand, patients with wheat flour allergy after ingestion and/or with baker's asthma were not sensitised to wheat pollen, despite it containing some common allergens. In the same way, all our asthmatic bakers (135 patients) tolerated the ingestion of bread. Here we try to explain the reason for these surprising observations.     

The effect of pet ownership on the risk of allergic sensitisation and bronchial asthma

An increasing volume of evidence suggests that early contact of children with the allergens of furred pets (especially those produced by cats) may determine a lower risk of developing allergic sensitisation to these materials. A possible explanation of this data is that an early inhalation of high levels of the major cat allergen Fel d 1 induces the production of IgG and IgG4 antibodies with a "protective" effect. Other authors have shown that the prevalence of allergic sensitisation to cats, in adults, is reduced in those patients exposed to the lowest and highest levels of the allergens. On the contrary, the risk of developing sensitisation to cats is significantly higher when the patients were exposed to intermediate levels of Fel d 1. Moreover, epidemiological studies have demonstrated a relatively low prevalence of cat allergy (about 10%) in some countries where rates of cat ownership are high. This data confirms the role of indirect exposure to pet allergens in inducing allergic sensitisation. Clothes of pet owners have been indicated as the carriers for the dispersal of these allergens in pet-free environments. However, it is important to point out that exposure of highly sensitised patients to relevant amounts of pet allergens (such as in a pet shows/shops) may determine a dramatic exacerbation of nasal and/or bronchial symptoms.     

Assessment of Cardiovascular Risk

Atherosclerotic cardiovascular disease (CVD) is the most common cause of death worldwide. Usually atherosclerosis is caused by the combined effects of multiple risk factors. For this reason, most guidelines on the prevention of CVD stress the assessment of total CVD risk. The most intensive risk factor modification can then be directed towards the individuals who will derive the greatest benefit. To assist the clinician in calculating the effects of these multiple interacting risk factors, a number of risk estimation systems have been developed. This review address several issues regarding total CVD risk assessment:

• Why should total CVD risk be assessed?
• What risk estimation systems are available?
• How well do these systems estimate risk?
• What are the advantages and disadvantages of the current systems?
• What are the current limitations of risk estimation systems and how can they be resolved?
• What new developments have occurred in CVD risk estimation?

     

Wheat flour allergy: an entire diagnostic tool for complex allergy

Wheat proteins are involved in respiratory allergy, contact allergy and food allergy. Wheat allergens involve in these pathologies are well-known. However, establishment of wheat allergy diagnostic can be sometimes difficult on account of the complex allergenic composition of skin prick test (SPT) solutions of wheat flour. Therefore, we have studied specific IgE reactivity from patient sera with wheat food allergy, and characterized allergenic composition of wheat SPT solutions by specific antibodies directed to wheat allergens. The results showed that 20 of the 25 sera analyzed contained specific IgE to at least one wheat protein fraction. Among positive sera, 75% have specific IgE to water/salt soluble fraction, 85% to native gluten fractions and 65% to wheat isolate fraction. The results showed also that SPT solutions of wheat flour contained major food allergens from each allergenic fraction. These results highlighted the importance of using fractions, which constitute the whole wheat allergenic pattern, during specific IgE reactivity analyses. Moreover, we have observed that wheat isolate extract (results of food industrial process) contained not only modified allergens (neo-allergens) involve of specific food allergy to wheat isolate but also some native allergens involve in wheat food allergy. Thus, these results showed the importance to use, for wheat in vivo diagnosis together wheat SPT solutions (gluten extract and wheat isolate) in order to differentiate wheat food allergy to specific wheat isolate allergy.     

Anaphylaxis in Children: Current Understanding and Key Issues in Diagnosis and Treatment

Anaphylaxis is a severe allergic reaction that is rapid in onset and may cause death. Since it is unpredictable and potentially fatal, prompt recognition and treatment are vital to maximize a positive outcome. The occurrence of anaphylaxis is increasing across all ages in the United States, with increased risk of worse outcome in teenagers/young adults and in those with comorbid conditions such as asthma. Gaps in the assessment of patient-specific risk factors, identification and prevention of triggers, recognition of signs/symptoms, and pharmacologic treatment of anaphylaxis have been identified at the physician and caregiver/patient level. A PubMed literature search (January 2000?CDecember 2011) was conducted to identify publications on childhood anaphylaxis using the following terms: food allergy, food allergens, food hypersensitivity, epinephrine, epinephrine auto-injectors, anaphylactic triggers, and anaphylaxis. This review will critically appraise these key issues and highlight strategies that might result in improved management of anaphylaxis in children.     

Pathogenesis and treatment of hepatitis e virus infection

Hepatitis E has been considered to be a travel-associated, acute, self-limiting liver disease that causes fulminant hepatic failure in specific high-risk groups only. However, hepatitis E virus (HEV) infection can also be acquired in industrialized countries-HEV genotype 3 infection is a zoonosis, with pigs and rodents serving as animal reservoirs. In recent years, cases of chronic HEV infection that were associated with progressive liver disease have been described in several cohorts of immunocompromised individuals, including recipients of organ transplants. The topic of hepatitis E is therefore re-emerging and has raised the following important questions: what is the risk for HEV infection in Western countries (eg, from eating uncooked meat)? How frequently does chronic hepatitis E develop among human immunodeficiency virus-infected patients and recipients of organ transplants? What are the treatment options? What is the current status of vaccine development? What do we know about the pathogenesis of HEV infection, and why does it have a more severe course in pregnant women? This review summarizes the current knowledge on the pathogenesis and treatment of HEV infection.     

Diagnosis of Prostate Cancer: The Clinical Use of Transrectal Ultrasound and Biopsy

A number of diagnostic dilemmas arise regarding diagnosis of prostate cancer. Undoubtedly transrectal ultrasound (TRUS) guided prostate biopsy has become standard in urology to diagnose prostate cancer. Nevertheless a lot of questions regarding the clinical use of TRUS-biopsy are open. Should we perform lesion-directed or random biopsies? How many biopsy cores should be obtained for optimal diagnostic yield, to reduce the incidence of false-negative biopsies? What areas of the prostate should be biopsied to give the best diagnostic results? If the initial biopsy fails to detect cancer, who should undergo repeat biopsy? And how often should we repeat it? What role do PSA and PSA parameters such as PSAD, PSA-TZ, PSAV, percent-free PSA play in findings upon the outcome of repeat biopsies? What role plays prostate volume or age? Are cancers detected on multiple repeat biopsies clinically “significant” and thus deserve therapy? In this review answers regarding these questions are given using the recent literature and the results of the European Prostate Cancer Detections Study (EPCDS).     

Biology of tree pollen allergens

More than 25% of the population suffer from type I allergy. Pollens from trees of the Fagales, Oleaceae, and Cupressaceae belong to the most potent and frequent allergen sources. During the past 15 years, the nature of the most important allergens has been identified by molecular biological techniques, and recombinant allergens equivalent to the natural allergens have been produced. These advances provide insight into the biological functions of important allergens and allow the development of novel forms of diagnosis and therapy. In this review, we focus on Fagales allergens to illustrate the impact of recombinant allergens on diagnosis and therapy. We discuss structural similarities as a molecular basis for crossreactivities and develop diagnostic concepts by using speciesspecific marker allergens as well as highly cross-reactive allergens. The identification of the allergen recognition profiles of patients with recombinant allergens allows a more precise selection of patients for available forms of allergy treatment. Moreover, we describe novel recombinant allergen-based forms of specific immunotherapy.     

Cereal pollen sensitisation in pollen allergic patients: to treat or not to treat?

Pollen allergens of the Poaceae family comprise one of the main causes of pollinosis worldwide. Although most of cereals are included in this family, certain pollination characteristics and aerobiological features differentiate them from common wild grass pollen. Cereal pollen grains cannot be easily characterised as potential sources of aero allergens, because of their pollination mode (most of them are autogamous plants), the consecutive low numbers of pollen they produce and their pollen's large volume and consequent high weight which further prevent dispersion and pollen transport. However, various epidemiologicalstudies concluded in comparable sensitisation patterns between common grass and cereal pollen. This fact can be attributed to the common epitopes shared between grass and cereal pollen allergens, which are responsible for the high cross reactivity observed not only in vitro but also in vivo. Therefore, the sensitisation patterns do not usually reflect a genuine, cereal-specific IgE recognition. On the contrary, genuine cereal sensitisation and allergy are referred to only in rare cases of occupational exposure to high amounts of these pollen grains (farmers and field workers) or in patients staying in the vicinity of cereal fields. Thus, cautious considerations should be taken into account when diagnostically approaching patients in which cereal pollen allergy could be considered in the differential diagnosis.     

Quand pratiquer un bilan allergologique en pathologie oculaire ?

Ocular allergy can take several different clinical forms, including those in which IgE-mediated reactions are predominant or in others where they are an aggregating factor. The need for an allergy workup varies depending on the clinical manifestations. Pollen-induced conjunctivitis, so-called seasonal pollinosis, is in general easily diagnosed and the allergy workup is used only to confirm the identity of the responsible allergen(s). Conjunctivitis associated with perennial allergens is sometimes more difficult to diagnose, in which case the allergy workup is a essential diagnostic element. However, allergic sensitisation is not always synonymous with allergic conjunctivitis, and other local examinations, such as a conjunctival provocation test, are sometimes necessary to establish the diagnosis. Atopic vernal keratoconjunctivitis and atopic keratoconjunctivitis are two special forms of keratoconjunctivitis, the first involving pre-pubertal males and the second involving young adults with a history of atopic dermatitis. In these two conditions, conjunctival sensitisation is not the principal mechanism, but it can aggravate the disease. Results of an allergy workup can provide evidence for recommending avoidance of the allergen(s) or specific immunotherapy, which may ameliorate the evolution of the disease. Contact eczema may require a dermatological workup when the allergen has not been identified in the allergy workup. Finally, certain cases of chronic conjunctivitis occurring in association with dry eye syndrome or with blepharitis, such as ocular rosacea, can look like allergic conjunctivitis and vice versa. An allergy workup is then an important diagnostic element. Thus, an allergy workup has a variable but often important place in the care of patients with conjunctivitis.     

Indoor Allergens and Allergic Respiratory Disease

Purpose of review

The purpose of this review is to evaluate the most recent findings on indoor allergens and their impact on allergic diseases.

Recent findings

Indoor allergens are present inside buildings (home, work environment, school), and given the chronic nature of the exposures, indoor allergies tend to be associated with the development of asthma. The most common indoor allergens are derived from dust mites, cockroaches, mammals (including wild rodents and pets), and fungi. The advent of molecular biology and proteomics has led to the identification, cloning, and expression of new indoor allergens, which have facilitated research to elucidate their role in allergic diseases. This review is an update on new allergens and their molecular features, together with the most recent reports on their avoidance for allergy prevention and their use for diagnosis and treatment.

Summary

Research progress on indoor allergens will result in the development of new diagnostic tools and design of coherent strategies for immunotherapy.

     

RSV bronchiolitis and risk of wheeze and allergic sensitisation in the first year of life.

Severe respiratory syncytial virus (RSV) infection has been hypothesised to be a risk factor for the development of allergy and asthma, but epidemiological studies in older children have been inconclusive. The current study hypothesises that the effect of RSV bronchiolitis might be most prominent during the first year after bronchiolitis. Forty-two infants had experienced RSV bronchiolitis severe enough to cause hospitalisation. For each child with RSV infection, two controls were acquired from a birth cohort and matched for date of birth and sex. All the children were followed prospectively and underwent a follow-up examination at a mean age of 1 yr, which included physical examination, and serum immunoglobulin (Ig) E tests for common food and inhaled allergens. Risk factors for the development of recurrent wheezing and IgE antibodies were analysed for the whole group of 126 children. A positive test for IgE antibodies was noted in 14 of 42 (33%) RSV children and in 2 of 84 (2.3%) children in the control group. RSV bronchiolitis was the most important risk factor for allergic sensitisation. Likewise, 13 children (15.5%) of the RSV group and three (3.6%) children of the control group suffered from recurrent wheezing, and RSV bronchiolitis posed a considerable risk for recurrent wheezing. Severe respiratory syncytial virus bronchiolitis during the first year of life is an important risk factor for the development of recurrent wheezing and sensitisation to common allergens during the subsequent year.     

Allergic sensitisation in tuberculosis patients at the time of diagnosis and following chemotherapy

Background  

It is still a matter of debate whether there is an association between infection with Mycobacterium tuberculosis (M. tuberculosis) and allergy. Previously, we have shown higher levels of specific IgE to different inhalant allergens and total IgE in tuberculosis (TB) patients compared to controls. The objectives of this study were to evaluate a possible change in allergic sensitisation after successful TB treatment and to confirm the finding of our previous study of enhanced allergic sensitisation in TB patients compared to controls in a more controlled setting. Additionally, we wanted to determine the cytokine profile in the same groups and finally to evaluate the association between the presence of Bacillus Calmette-Guérin vaccination (BCG) scar and allergic sensitisation among the controls.     

Component-resolved diagnosis in hymenoptera allergy

Component-resolved diagnosis based on the use of well-defined, properly characterised and purified natural and recombinant allergens constitutes a new approach in the diagnosis of venom allergy. Prospective readers may benefit from an up-to-date review on the allergens. The best characterised venom is that of Apis mellifera, whose main allergens are phospholipase A2 (Api m1), hyaluronidase (Api m2) and melittin (Api m4). Additionally, in recent years, new allergens of Vespula vulgaris have been identified and include phospholipase A1 (Ves v1), hyaluronidase (Ves v2) and antigen 5 (Ves v5). Polistes species are becoming an increasing cause of allergy in Europe, although only few allergens have been identified in this venom.In this review, we evaluate the current knowledge about molecular diagnosis in hymenoptera venom allergy.